Electronic device and method for controlling slew rate for high-speed data communications

ABSTRACT

An electronic device and a method of controlling a slew rate for high-speed data communications are provided. The electronic device, according to an embodiment of the disclosure, includes a serializer configured to receive parallel data from another electronic device along with clock rate information, and convert the parallel data into serial data. The electronic device further includes a delay generator configured to generate a delay in the converted serial data using the clock rate information. The electronic device further includes a multiplexer configured to multiplex the converted serial data of the non-slew mode with the delayed data of the slew mode. The electronic device further includes a plurality of driver legs configured to receive the multiplexed data, and transfer the multiplexed data to the another electronic device. The electronic device further includes at least one of a voltage-controlled oscillator and a current-controlled oscillator configured to generate the clock rate information.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of priority to Indian Patent ApplicationNo. 202241011562, filed on Mar. 3, 2022, in the Indian Patent Office,the disclosure of which is incorporated by reference herein in itsentirety.

BACKGROUND 1. Field

The present disclosure relates to high-speed data communications, andmore specifically, to an electronic device and a method for controllingslew rate for the high-speed data communications.

2. Description of Related Art

In general, a demand for higher data rates has exponentially increasedin conventional electronic devices, such as smartphones, laptops, etc.For example, widespread use of 3rd Generation (3G), Long-Term Evolution(LTE), and upcoming 4G technologies have significantly enhanced datarates in the electronic devices. In another example, mobile phonecameras have begun to support 5M pixels and greater as a common feature.With increased resolution and larger sizes, displays have become morecomplex. Indeed, several manufacturers have recently usedthree-dimensional (3D) display technology in mobile phones. In addition,the size and performance of solid-state memory storage have increased.These factors may raise the data rate needs of certain peripherals. Tokeep up with the rising data rate demand, the electronic devices mayinclude one or more application processors, which analyze data andconnect the electronic device to various services (e.g., transmitsignal) that may require a high bandwidth pipe and/or a high-frequencyband. A Mobile Industrial Processor Interface (MIPI) standard (e.g.,D-PHY, M-PHY, etc.) is frequently used to transmit such a signal in ahigh-frequency spectrum between the application processors and/or theelectronic devices, which specifies interfaces between components (e.g.,Serial Advanced Technology Attachment (SATA), Peripheral ComponentInterconnect (PCI), Universal Serial Bus (USB), etc.) of the electronicdevices.

The M-PHY provides asynchronous data rates in excess of 5 Gigabits persecond (Gbps), allowing designers to accelerate memory transfer andCamera Serial Interface (CSI)/Display Serial Interface (DSI) interfacespeeds. The M-PHY is a successor to the D-PHY, featuring fewer pins andhigher bandwidth per pin, as well as increased power efficiency. Datatransfer in the M-PHY can be burst or continuous, and data transfers canbe performed in a High Speed (HS) mode or a Low Speed (LS) mode. A LargeAmplitude (LA) and a Small Amplitude (SA) driving strengths aresupported by the M-PHY. Based on the signalling system utilized in theLS mode, the M-PHY supports two types of modules: Type-I and Type-II. Inthe LS mode, the signalling strategy might be Pulse Width Modulation(PWM) or Non-Return to Zero (NRZ). Where the PWM is used in the Type-I,and a clock is incorporated in data lanes. The data rates in the PWMmode are determined by gears that are supported. For example, alow-speed gear (e.g., G0 mode) employs a data rate as low as 10 Kilobitsper second (Kbps). Furthermore, the G1 mode is a standard required gearwith the data rate ranging from 3 Megabits per second (Mbps) to 9 Mbps.Each extra gear boosts the data rate by a factor of two (e.g., a G2 modesupports 6 Mbps to 18 Mbps). While the Type-I covers gears up to a G7mode, gears up to a G5 mode are expected to be more extensively utilizedin terms of power. The Type-II (e.g., system mode) is source synchronousin that a clock is needed to sample the data. The clock is common toboth a transmitter and a receiver. The system mode signaling isrelatively straightforward and hence easy to implement in systems notwishing to have the PWM mode.

While using the G1 mode of the M-PHY, several difficulties such ascommon-mode noise and electromagnetic interference (EMI) may beobserved. To control the common mode noise and the EMI, a transmitteroutput may be slewed at certain rates (e.g., volts per nanosecond(V/ns)). However, controlling slew rates is difficult due to range andgranularity limitations. For example, the G1 mode of the M-PHY has aminimum slew rate of 0.35 V/ns, a maximum slew rate of 0.9 V/ns, and anintermediate slew rate that covers a minimum and maximum limits with agranularity/resolution limit of 1 to 30%.

Certain slew rate controlling mechanisms are available for anon-serializer/deserializer application of the M-PHY whose drivers aredifferent than a serializer/deserializer application of the M-PHY. Forexample, the non-serializer/deserializer application controls the slewrate via capacitors and/or feed-forward transistors in output drivercircuits. Because all such implementations severely influence the drivecircuits by adding additional capacitive loads, this mechanism is onlyrelevant to the G1 mode of the M-PHY and not to other modes (e.g., G2-G5non-slew high-speed modes). As a result, conventionalnon-serializer/deserializer slew control mechanisms cannot be used forthe serializer/deserializer applications of the M-PHY.

Thus, it is desired to provide a useful alternative for controlling theslew rate for high-speed data communications (e.g., M-PHY).

SUMMARY

The embodiments herein provide for control of a slew rate for high-speeddata communications. According to an embodiment of the presentdisclosure, a serializer of a first electronic device receives paralleldata from a second electronic device along with clock rate informationand converts the parallel data to serial data. The parallel data isreceived in one of a slew mode (e.g., G1, low-speed gear) and a non-slewmode (e.g., G2-G5, high-speed gear). The clock rate information isreceived via the Phase Lock Loop (PLL) of the first electronic device. Adelay generator of the first electronic device generates a delay in theconverted serial data of the slew mode using the clock rate information.The multiplexer of the first electronic device multiplexes the convertedserial data of the non-slew mode with the delayed data of the slew modeat a plurality of pre-driver legs to control the slew rate. As a result,a proposed architecture of the first electronic device may meetspecifications for M-PHY slew standards and/or other technologies. Theaspects presented herein allow for no significant impact on non-slewoutput driver legs. That is, no impact on high-speed path layout (anon-slew data path) may occur, because the delay generator is onlyincluded for a slew data path.

Another embodiment presented herein provides for the first electronicdevice to sequentially arranging a plurality of electronic components tocontrol the delay. The plurality of electronic components include adelayed clock, an exclusive-OR (XOR) gate, a Low Pass Filter (LPF), acomparator, and a delay control apparatus.

Another embodiment presented herein provides to configure a flexibleslew rate by generating a linear delay using RC devices, where the RCdevices include a plurality of resistors and a plurality of capacitors,and/or by generating a parabolic delay using a Metal Oxide Silicon (MOS)transistor.

Another embodiment presented herein provides to avoid utilizing a selectline of the multiplexer, which reduces the number of Field EffectTransistors (FETs) in the plurality of pre-driver legs.

Accordingly, embodiments herein disclose a first electronic device forcontrolling a slew rate for high-speed data communications. The firstelectronic device includes a serializer configured to receive paralleldata from at least one second electronic device along with clock rateinformation, and convert the parallel data into serial data. Theparallel data is received in one of a slew mode and a non-slew mode. Theclock rate information is received from a Phase Lock Loop (PLL) of thefirst electronic device. The first electronic device further includes adelay generator configured to generate a delay in the converted serialdata using the clock rate information, where the converted serial datais in the slew mode. The first electronic device further includes amultiplexer configured to multiplex the converted serial data of thenon-slew mode with the delayed data of the slew mode at a plurality ofpre-driver legs of the first electronic device to control the slew rate.The first electronic device further includes a plurality of driver legsconfigured to receive the multiplexed data from the plurality ofpre-driver legs, and transfer the multiplexed data to the at least onesecond electronic device. The first electronic device further includesat least one of a Voltage-Controlled Oscillator (VCO) and aCurrent-Controlled Oscillator (CCO) configured to generate the clockrate information, where the clock rate information includes a half-rateclock.

In an embodiment, the delay generator includes a delayed clock, anexclusive-OR (XOR) gate, a Low Pass Filter (LPF), a comparator, and adelay control apparatus, where the delayed clock, the XOR gate, the LPF,the comparator, and the delay control apparatus are arrangedsequentially to control the delay.

In an embodiment, the delay generator is further configured to configurea flexible slew rate, wherein to configure the flexible slew rate, thedelay generator is configured to generate a linear delay using RCdevices, where the RC devices include a plurality of resistors and aplurality of capacitors, and/or generate a parabolic delay using a MetalOxide Silicon (MOS) transistor.

In an embodiment, the multiplexer is configured to prevent use a selectline of the multiplexer, and to reduce a number of Field EffectTransistors (FETs) in the plurality of pre-driver legs.

In an embodiment, the slew mode includes a low-speed gear, and thenon-slew mode includes at least one high-speed gear.

In an embodiment, the delay generator is further configured to determinea minimum slew rate and a maximum slew rate using the RC devices. Thedelay generator is further configured to determine at least oneintermediate slew rate based on the minimum slew rate and the maximumslew rate using a delay control apparatus of the delay generator. Thedelay generator is further configured to store the minimum slew rate,the maximum slew rate, and the at least one intermediate slew rate. Thedelay generator is further configured to receive data from theserializer, where the received data is in the slew mode. The delaygenerator is further configured to generate the delay on the receiveddata using the stored minimum slew rate, the stored maximum slew rate,and the stored at least one intermediate slew rate.

In an embodiment, the delay generator is further configured to receivethe half-rate clock from the PLL. The delay generator is furtherconfigured to apply the half-rate clock to the RC devices to generate adelayed half-rate clock. The delay generator is further configured toextract a difference between the received half-rate clock and thedelayed half-rate clock. The delay generator is further configured todetermine whether the difference is within a threshold range of the slewmode. The threshold range includes the minimum slew rate and the maximumslew rate. The delay generator is further configured to perform one of:adjust the difference using a feedback mechanism in response todetermining that the difference is not within threshold range of theslew mode and storing the minimum slew rate and the maximum slew rate,or store the minimum slew rate and the maximum slew rate in response todetermining that the difference is within threshold range of the slewmode.

Accordingly, embodiments herein disclose a method for controlling theslew rate for high-speed data communications. The method includesreceiving, by the serializer of the first electronic device, paralleldata from at least one second electronic device along with clock rateinformation. The serializer converting the parallel data into serialdata. The parallel data being received in one of a slew mode and anon-slew mode. The clock rate information being received from the PLL ofthe first electronic device. The method further includes generating, bya delay generator of the first electronic device, a delay in theconverted serial data using the clock rate information, where theconverted serial data is in the slew mode. The method further includesmultiplexing, by a multiplexer of the first electronic device, theconverted serial data of the non-slew mode with the delayed data of theslew mode at a plurality of pre-driver legs of the first electronicdevice to control the slew rate.

These and other aspects of the embodiments herein will be betterappreciated and understood when considered in conjunction with thefollowing description and the accompanying drawings. It should beunderstood, however, that the following descriptions, while indicatingpreferred embodiments and numerous specific details thereof, are givenby way of illustration and not of limitation. Many changes andmodifications may be made within the scope of the embodiments herein,and the embodiments herein include all such modifications.

BRIEF DESCRIPTION OF THE DRAWINGS

This invention is illustrated in the accompanying drawings, throughoutwhich like reference letters indicate corresponding parts in the variousfigures. The embodiments herein will be better understood from thefollowing description with reference to the drawings, in which:

FIG. 1 illustrates a block diagram of a first electronic device forcontrolling a slew rate for high-speed data communications, according toan embodiment as disclosed herein;

FIG. 2 is a flow diagram illustrating a method for controlling the slewrate for the high-speed data communications, according to an embodimentas disclosed herein;

FIGS. 3A-3B are a flow diagram illustrating a method for generating adelay in converted serial data using clock rate information, accordingto an embodiment as disclosed herein;

FIGS. 4A-4B illustrate an example circuit diagram of a delay generatorfor controlling the slew rate for the high-speed data communications andan example of output waveform having a slew generated by the firstelectronic device, according to an embodiment as disclosed herein; and

FIGS. 5A-5C illustrate example circuit diagrams of a pre-driver leg in anon-slew mode and a slew mode, according to an embodiment as disclosedherein.

DETAILED DESCRIPTION OF THE INVENTION

The embodiments herein and the various features and advantageous detailsthereof are explained more fully with reference to the non-limitingembodiments that are illustrated in the accompanying drawings anddetailed in the following description. Descriptions of well-knowncomponents and processing techniques are omitted so as to notunnecessarily obscure the embodiments herein. Also, the variousembodiments described herein are not necessarily mutually exclusive, assome embodiments can be combined with one or more other embodiments toform new embodiments. The term “or” as used herein, refers to anon-exclusive or, unless otherwise indicated. The examples used hereinare intended merely to facilitate an understanding of ways in which theembodiments herein can be practiced and to further enable those skilledin the art to practice the embodiments herein. Accordingly, the examplesshould not be construed as limiting the scope of the embodiments herein.

As is traditional in the field, embodiments may be described andillustrated in terms of blocks which carry out a described function orfunctions. These blocks, which may be referred to herein as units ormodules or the like, are physically implemented by analog or digitalcircuits such as logic gates, integrated circuits, microprocessors,microcontrollers, memory circuits, passive electronic components, activeelectronic components, optical components, hardwired circuits, or thelike, and may optionally be driven by firmware. The circuits may, forexample, be embodied in one or more semiconductor chips, or on substratesupports such as printed circuit boards and the like. The circuitsconstituting a block may be implemented by dedicated hardware, or by aprocessor (e.g., one or more programmed microprocessors and associatedcircuitry), or by a combination of dedicated hardware to perform somefunctions of the block and a processor to perform other functions of theblock. Each block of the embodiments may be physically separated intotwo or more interacting and discrete blocks without departing from thescope of the invention. Likewise, the blocks of the embodiments may bephysically combined into more complex blocks without departing from thescope of the invention

The accompanying drawings are used to help easily understand varioustechnical features and it should be understood that the embodimentspresented herein are not limited by the accompanying drawings. As such,the present disclosure should be construed to extend to any alterations,equivalents and substitutes in addition to those which are particularlyset out in the accompanying drawings. Although the terms first, second,etc. may be used herein to describe various elements, these elementsshould not be limited by these terms. These terms are generally onlyused to distinguish one element from another.

Throughout this disclosure, the terms “mux” and “multiplexer” are usedinterchangeably and means the same. The terms “mux data” and“multiplexed data” are used interchangeably and means the same.

Accordingly, embodiments herein disclose a first electronic device forcontrolling a slew rate for high-speed data communications. The firstelectronic device includes a serializer for receiving parallel data froma second electronic device (e.g., a digital circuit) along with a clockrate information and converting the parallel data into serial data,where the parallel data is received in one of a slew mode and a non-slewmode, and the clock rate information is received from a Phase Lock Loop(PLL) of the first electronic device. Further, the first electronicdevice includes a delay generator for generating a delay in theconverted serial data using the clock rate information, where theconverted serial data is in the slew mode. Further, the first electronicdevice includes a mux for multiplexing the converted serial data of thenon-slew mode with the delayed data of the slew mode at a plurality ofpre-driver legs of the first electronic device to control the slew rate.Further, the first electronic device includes a plurality of driver legsfor receiving the mux data from the plurality of pre-driver legs andtransferring to the second electronic device. Further, the firstelectronic device includes a voltage-controlled oscillator (VCO) and/ora current-controlled oscillator (CCO) for generating the clock rateinformation, where the clock rate information includes a half-rateclock.

Accordingly, embodiments herein disclose a method for controlling theslew rate for high-speed data communications. The method includesreceiving, by the serializer of the first electronic device, paralleldata from the second electronic device along with the clock rateinformation, where the serializer converts the parallel data into serialdata and the parallel data is received in one of a slew mode and anon-slew mode and the clock rate information is received from the PLL ofthe first electronic device. Further, the method includes generating, bythe delay generator of the first electronic device, the delay in theconverted serial data using the clock rate information, where theconverted serial data is in the slew mode. Further, the method includesmultiplexing, by the mux of the first electronic device, the convertedserial data of the non-slew mode with the delayed data of the slew modeat the plurality of pre-driver legs of the first electronic device tocontrol the slew rate.

Unlike conventional methods and systems, the proposed method allows thefirst electronic device to control a slew rate for high-speed datacommunications. The serializer of the first electronic device receivesparallel data from the second electronic device along with clock rateinformation and converts the parallel data to serial data. The receivingparallel data is received in one of a slew mode (e.g., G1, low-speedgear) and a non-slew mode (e.g., G2-G5, high-speed gear), and the clockrate information is received via the PLL of the first electronic device.Then, using the clock rate information, the delay generator of the firstelectronic device generates the delay in the converted serial data ofthe slew mode. The mux of the first electronic device then multiplexesthe converted serial data of the non-slew mode with the delayed data ofthe slew mode at the plurality of pre-driver legs to control the slewrate. As a result, a proposed architecture of the first electronicdevice may meet specifications for M-PHY slew standards and/or othertechnologies. The aspects presented herein allow for no significantimpact on non-slew output driver legs. That is, no impact on high-speedpath layout (a non-slew data path) may occur, because the delaygenerator is only included for a slew data path.

Unlike conventional methods and systems, the proposed method allows thefirst electronic device to sequentially arrange a plurality ofelectronic components to control the delay. The plurality of electroniccomponents include a delayed clock, an exclusive-OR (XOR) gate, a LowPass Filter (LPF), a comparator, and a delay control apparatus.

Unlike conventional methods and systems, the proposed method allows thefirst electronic device to configure a flexible slew rate by generatinga linear delay using RC devices, where the RC devices include aplurality of resistors and a plurality of capacitors, and/or bygenerating a parabolic delay using a Metal Oxide Silicon (MOS)transistor.

Unlike conventional methods and systems, the proposed method allows thefirst electronic device to avoid utilizing a select line of the mux,which reduces the number of Field Effect Transistors (FETs) in theplurality of pre-driver legs.

Referring now to the drawings, and more particularly to FIGS. 1 through5C, where similar reference characters denote corresponding featuresconsistently throughout the figures, there are shown preferredembodiments.

FIG. 1 illustrates a block diagram of a first electronic device (100)for controlling a slew rate for high-speed data communications,according to an embodiment as disclosed herein. Examples of the firstelectronic device (100) include, but are not limited to, a communicationinterface (e.g., Serial Advanced Technology Attachment (SATA), aPeripheral Component Interconnect (PCI), a Universal Serial Bus (USB),etc.).

The first electronic device (100) is implemented by processing circuitrysuch as logic gates, integrated circuits, microprocessors,microcontrollers, memory circuits, passive electronic components, activeelectronic components, optical components, hardwired circuits, or thelike, and may optionally be driven by firmware. The circuits may, forexample, be embodied in one or more semiconductor chips, or on substratesupports such as printed circuit boards and the like.

In an embodiment, the first electronic device (100) includes aserializer (101), a delay generator (102), a plurality of pre-driverlegs (103), and a plurality of driver legs (104).

The serializer (101) receives parallel data from a second electronicdevice (e.g., a digital circuit) (not shown in FIG. 1 ) along with aclock rate information and converts the parallel data into serial data,where the parallel data is received in a slew mode or a non-slew modeand the clock rate information is received from a PLL (not shown in FIG.1 ) of the first electronic device (100). The slew mode includes alow-speed gear (e.g., G1) and the non-slew mode includes a high-speedgear (e.g., G2, G3, G4, G5, etc.). A VCO or a CCO of the PLL generatesthe clock rate information, where the clock rate information includes ahalf-rate clock.

The delay generator (102) generates a delay in the received paralleldata using the clock rate information, where the converted serial datais in the slew mode. The delay generator (102) includes a delayed clock,an XOR gate, a LPF, a comparator, and a delay control apparatus arearranged sequentially to control the delay. The delay control apparatusconfigures a flexible slew rate by generating a linear delay using RCdevices, where the RC devices include a plurality of resistors and aplurality of capacitors and/or by generating a parabolic delay using aMOS transistor.

Alternatively or additionally, the delay generator (102) receives thehalf-rate clock from the PLL. The delay generator (102) applies thehalf-rate clock to the RC devices to generate a delayed half-rate clock.The delay generator (102) extracts a difference between the receivedhalf-rate clock and the delayed half-rate clock. The delay generator(102) determines whether the difference is within a threshold range ofthe slew mode (e.g., a minimum slew rate of 0.35 V/ns, a maximum slewrate of 0.9 V/ns), where the threshold range includes the minimum slewrate and the maximum slew rate. The delay generator (102) increases ordecreases (e.g., adjusts) the difference using a feedback mechanism inresponse to determining that the difference is not within the thresholdrange of the slew mode and stores the minimum slew rate and the maximumslew rate. The delay generator (102) stores the minimum slew rate andthe maximum slew rate in response to determining that the difference iswithin the threshold range of the slew mode.

Alternatively or additionally, the delay generator (102) determines oneor more intermediate slew rates based on the minimum slew rate and themaximum slew rate using the delay control apparatus. The delay generator(102) stores the minimum slew rate, the maximum slew rate, and the oneor more intermediate slew rates. The delay generator (102) receives datafrom the serializer (101), where the received data is in the slew mode.The delay generator (102) generates the delay on the received data usingthe stored minimum slew rate, the maximum slew rate, and the one or moreintermediate slew rates to minimize a common-mode noise and anelectromagnetic interference (EMI).

Then, a mux (not shown in FIG. 1 ) multiplexes the converted serial dataof the non-slew mode with the delayed data of the slew mode at theplurality of pre-driver legs (103) of the first electronic device (100)to control the slew rate. The plurality of driver legs (104) receivesthe mux data from the plurality of pre-driver legs (103) and transfersto the second electronic device.

Although FIG. 1 shows various hardware components of the firstelectronic device (100), it is to be understood that other embodimentsare not limited thereon. In other embodiments, the first electronicdevice (100) may include less or more components. Further, the labelsand/or names of the components are used only for illustrative purposesand do not limit the scope of the invention. For example, one or morecomponents can be combined together to perform same or substantiallysimilar functionality to control the slew rate for the high-speed datacommunications.

FIG. 2 is a flow diagram (200) illustrating a method for controlling theslew rate for the high-speed data communications, according to anembodiment as disclosed herein. The first electronic device (100)performs steps (201-206) of the flow diagram (200) to control the slewrate for the high-speed data communications.

At step (201), the method includes receiving the parallel data from thesecond electronic device along with the clock rate information. At step(202), the method includes converting the parallel data into serial dataand detecting that the converted serial data is in the slew mode or thenon-slew mode. At step (203), the method includes determining whetherthe converted serial data is in the slew mode or the non-slew mode. Atstep (204), the method includes generating the delay in the convertedserial data using the clock rate information in response to determiningthat the converted serial data is in the slew mode. At step (205), themethod includes multiplexing the converted serial data of the non-slewmode with the delayed data of the slew mode at the plurality ofpre-driver legs (103) of the first electronic device (100) to controlthe slew rate in response to determining that the converted serial datais in the non-slew mode. At step (206), the method includes transferringthe mux data from the plurality of pre-driver legs (103) to theplurality of driver legs (104).

FIGS. 3A and 3B are a flow diagram (204) illustrating a method forgenerating the delay in converted serial data using clock rateinformation, according to an embodiment as disclosed herein. The firstelectronic device (100) performs steps (204 a-204 k) of the flow diagram(204) to generate the delay in the converted serial data using the clockrate information, as described in reference to step (204) of FIG. 2 .

Referring to FIG. 3A, at step (204 a), the method includes receiving thehalf-rate clock from the PLL. At step (204 b), the method includesapplying the half-rate clock to the RC devices to generate the delayedhalf-rate clock. At step (204 c), the method includes extracting thedifference between the received half-rate clock and the delayedhalf-rate clock. At steps (204 d) and (204 e), the method includesdetermining whether the difference is within the threshold range of theslew mode, where the threshold range includes the minimum slew rate andthe maximum slew rate. At step (2040, the method includes increasing ordecreasing (e.g., adjusting) the difference using the feedback mechanismto make the difference within the threshold range in response todetermining that the difference is not within the threshold range of theslew mode, and the method further flows to step (204 g).

Referring to FIG. 3B, at step (204 g), the method includes storing theminimum slew rate and the maximum slew rate in response to determiningthat the difference is within the threshold range of the slew mode.

At step (204 h), the method includes determining the one or moreintermediate slew rates based on the minimum slew rate and the maximumslew rate using the delay control apparatus. At step (204 i), the methodincludes storing the minimum slew rate, the maximum slew rate, and theone or more intermediate slew rates. At step (204 j), the methodincludes receiving data from the serializer (101), where the receiveddata is in the slew mode. At step (204 k), the method includesgenerating the delay on the received data using the stored minimum slewrate, the stored maximum slew rate, and the stored one or moreintermediate slew rates.

The various actions, acts, blocks, steps, or the like in the flowdiagrams (200 and 204) may be performed in the order presented, in adifferent order and/or simultaneously. Further, in some embodiments,some of the actions, acts, blocks, steps, or the like may be omitted,added, modified, skipped, or the like without departing from the scopeof the invention.

FIGS. 4A-4B illustrate an example circuit diagram of the delay generator(102) for controlling the slew rate for the high-speed datacommunications and an example of output waveform having the slewgenerated by the first electronic device (100), according to anembodiment as disclosed herein. The delay generator (102) includes thedelayed clock (401 a), the XOR gate (403), the LPF (404), the comparator(405), and the delay control apparatus (402), which are arrangedsequentially to control the delay.

Referring to FIG. 4A, the delay control apparatus (402) configures theflexible slew rate by generating the linear delay using RC devices,where the RC devices include the plurality of resistors and theplurality of capacitors and/or generating the parabolic delay using theMOS transistor.

For example, the delay control apparatus (402) receives the half-rateclock from the PLL, where the clock information is enabled using aselect line (e.g., cal en) of the multiplexer (401) (e.g., a mux). Thedelay control apparatus (402) applies the half-rate clock to the RCdevices to generate the delayed half-rate clock, extracts the differencebetween the received half-rate clock and the delayed half-rate clock,and determines whether the difference is within the threshold range ofthe slew mode, where the threshold range includes the minimum slew rateand the maximum slew rate. The delay control apparatus (402) increasesor decreases (e.g., adjusts) the difference using the feedback mechanismin response to determining that the difference is not within thethreshold range of the slew mode and stores the minimum slew rate andthe maximum slew rate in response to determining that the difference iswithin the threshold range of the slew mode. The delay control apparatus(402) then determines the one or more intermediate slew rates based onthe minimum slew rate and the maximum slew rate and stores the same.

In some embodiments, the delay control apparatus (402) stores theslew-required information (e.g., the minimum slew rate, the maximum slewrate, and the one or more intermediate slew rates). The delay controlapparatus (402) receives the slew data from the serializer (101), wherethe slew data is enabled using the select line (e.g., cal en) of themultiplexer (401). The delay control apparatus (402) generates the delayon the received data using the stored minimum slew rate, the storedmaximum slew rate, and the stored one or more intermediate slew rates.The XOR gate (403) generates an output of logical 1 only when either ofthe two inputs is logical 1. Thus, the delay of delay generator block isconverted into an XOR output duty cycle. The LPF (404) generates anaverage of the input signal. Thus, the delay is converted into LPFoutput voltage. The comparator (405) compares the voltage with referencevoltages to calibrate minimum, maximum, and intermediate codes.

Referring to FIG. 4B, the example of output waveform (407) having theslew generated by the first electronic device (100). Here, driver legsget same data input but with delay among them as per slew requirement.Thus, the output of driver is a stair-cased waveform which is nothingbut the required slewed output. The slewed output for different codes(e.g., minimum, maximum, intermediate) is shown in superimposed form in(408).

FIGS. 5A-5C illustrate example circuit diagrams of a pre-driver leg in anon-slew mode and a slew mode, according to an embodiment as disclosedherein.

Referring to FIG. 5A, a first example circuit (501) and a second examplecircuit (502) of the plurality of pre-driver legs (103) is shown. Ingeneral, three inputs are received by the mux (401) (e.g., A, B, S).Where “A” and “B” represent input lines (e.g., data and clock as shownin FIG. 4A) and “S” represents the select line (e.g., “cal en” as shownin FIG. 4A). When the value of the select line is zero, the output ofthe mux (401) is “A” (e.g., data). When the value of the select line isone, the output of the mux (401) is “B” (e.g., clock). The firstelectronic device (100) uses a two-input multiplexer architecture or, inother words, multiplexing does not use the select line of themultiplexer (401) which reduces the number of FETs/MOSFETs in theplurality of pre-driver legs (103) to avoid stacking/jitter in the firstelectronic device (100). Thus, when the value of the input line (e.g.,B) is zero, then the output of the multiplexer (401) is “A”, and whenthe value of the input line (e.g., A) is zero, then the output of themultiplexer (401) is “B”.

Referring to FIGS. 5B and 5C, the equivalent circuits of the examplecircuits (503) and (505) are given in equivalent example circuits (504)and (506) for non-slewed mode and slewed modes, respectively. Theequivalent circuits (504) and (506) are arrived at by applying theconditions given in reference to the previous section (i.e., along withbasic CMOS logic, for input at gate=0/1, PMOS is ON/OFF & NMOS isOFF/ON). The equivalent circuit (504) is essentially two back-to-backinverters, which is good in terms of jitter for G2-G5 modes, forexample. While the equivalent circuit (506) may introduce jitter as thepull-up & pull-down paths are asymmetric. However, the impact of thejitter may be minimal in low speed modes (e.g., G1).

The embodiments disclosed herein can be implemented using at least onehardware device and performing network management functions to controlthe elements.

The foregoing description of the specific embodiments will so fullyreveal the general nature of the embodiments herein that others can, byapplying current knowledge, readily modify and/or adapt for variousapplications such specific embodiments without departing from thegeneric concept, and, therefore, such adaptations and modificationsshould and are intended to be comprehended within the meaning and rangeof equivalents of the disclosed embodiments. It is to be understood thatthe phraseology or terminology employed herein is for the purpose ofdescription and not of limitation. Therefore, while the embodimentsherein have been described in terms of preferred embodiments, thoseskilled in the art will recognize that the embodiments herein can bepracticed with modification within the scope of the embodiments asdescribed herein.

What is claimed is:
 1. A first electronic device for controlling a slewrate for high-speed data communications, the first electronic devicecomprising: a serializer configured to receive parallel data from atleast one second electronic device along with clock rate information,and convert the parallel data into serial data, wherein the paralleldata is received in one of a slew mode and a non-slew mode, and whereinthe clock rate information is received from a phase lock loop (PLL) ofthe first electronic device; a delay generator configured to generate adelay in the converted serial data using the clock rate information,wherein the converted serial data is in the slew mode; a multiplexerconfigured to multiplex the converted serial data of the non-slew modewith the delayed data of the slew mode at a plurality of pre-driver legsof the first electronic device to control the slew rate; a plurality ofdriver legs configured to receive the multiplexed data from theplurality of pre-driver legs, and transfer the multiplexed data to theat least one second electronic device; and at least one of avoltage-controlled oscillator (VCO) and a current-controlled oscillator(CCO) configured to generate the clock rate information, wherein theclock rate information comprises a half-rate clock.
 2. The firstelectronic device of claim 1, wherein the delay generator comprises adelayed clock, an exclusive-OR (XOR) gate, a low-pass filter (LPF), acomparator, and a delay control apparatus, wherein the delayed clock,the XOR gate, the LPF, the comparator, and the delay control apparatusare arranged sequentially to control the delay in the converted serialdata.
 3. The first electronic device of claim 1, wherein the delaygenerator is further configured to configure a flexible slew rate,wherein to configure the flexible slew rate, the delay generator isconfigured to: generate a linear delay using RC devices, wherein the RCdevices comprises a plurality of resistors and a plurality ofcapacitors; and generate a parabolic delay using at least one metaloxide silicon (MOS) transistor.
 4. The first electronic device of claim1, wherein to multiplex the converted serial data, the multiplexer isconfigured to prevent use of a select line of the multiplexer, andreduce a number of field effect transistors (FETs) in the plurality ofpre-driver legs.
 5. The first electronic device of claim 1, wherein theslew mode comprises a low-speed gear, and the non-slew mode comprises atleast one high-speed gear.
 6. The first electronic device of claim 1,wherein to generate the delay in the converted serial data using theclock rate information, the delay generator is further configured to:determine a minimum slew rate and a maximum slew rate using RC devices;determine at least one intermediate slew rate based on the minimum slewrate and the maximum slew rate using a delay control apparatus of thedelay generator; store the minimum slew rate, the maximum slew rate, andthe at least one intermediate slew rate; receive data from theserializer, wherein the received data is in the slew mode; and generatethe delay on the received data using the stored the minimum slew rate,the stored maximum slew rate, and the stored at least one intermediateslew rate.
 7. The first electronic device of claim 6, wherein todetermine the minimum slew rate and the maximum slew rate using the RCdevices, the delay generator is further configured to: receive thehalf-rate clock from the PLL; apply the half-rate clock to the RCdevices to generate a delayed half-rate clock; extract a differencebetween the received half-rate clock and the delayed half-rate clock;and determine whether the difference is within a threshold range of theslew mode, wherein the threshold range comprises the minimum slew rateand the maximum slew rate; and perform one of: adjust the differenceusing a feedback mechanism in response to determining that thedifference is not within the threshold range of the slew mode andstoring the minimum slew rate and the maximum slew rate, or store theminimum slew rate and the maximum slew rate in response to determiningthat the difference is within the threshold range of the slew mode.
 8. Amethod for controlling a slew rate for high-speed data communications,the method comprising: receiving, by a serializer of a first electronicdevice, parallel data from at least one second electronic device alongwith clock rate information, wherein the serializer converts theparallel data into serial data, wherein the parallel data is received inone of a slew mode and a non-slew mode, and wherein the serializerreceives the clock rate information from a phase lock loop (PLL) of thefirst electronic device; generating, by a delay generator of the firstelectronic device, a delay in the converted serial data using the clockrate information, wherein the converted serial data is in the slew mode;and multiplexing, by a multiplexer of the first electronic device, theconverted serial data of the non-slew mode with the delayed data of theslew mode at a plurality of pre-driver legs of the first electronicdevice to control the slew rate.
 9. The method of claim 8, wherein thegenerating of the delay comprises controlling the delay with a delayedclock, an exclusive-OR (XOR) gate, a low-pass filter (LPF), acomparator, and a delay control apparatus of the delay generator,wherein the delayed clock, the XOR gate, the LPF, the comparator, andthe delay control apparatus are arranged sequentially.
 10. The method ofclaim 8, further comprising configuring, by the delay generator, aflexible slew rate, the configuring of the flexible slew ratecomprising: generating a linear delay using RC devices, wherein the RCdevices comprises a plurality of resistors and a plurality ofcapacitors; and generating a parabolic delay using at least one metaloxide silicon (MOS) transistor.
 11. The method of claim 8, wherein themultiplexing of the converted serial data of the non-slew mode with thedelayed data of the slew mode at the plurality of pre-driver legscomprising preventing use of a select line of the multiplexer, andreducing a number of field effect transistors (FETs) in the plurality ofpre-driver legs.
 12. The method of claim 8, wherein the clock rateinformation comprises a half-rate clock generated by at least one of avoltage-controlled oscillator (VCO) and a current-controlled oscillator(CCO) of the PLL.
 13. The method of claim 8, wherein the slew modecomprises a low-speed gear and the non-slew mode comprises at least onehigh-speed gear.
 14. The method of claim 8, wherein the generating ofthe delay in the converted serial data comprises: determining, by thedelay generator, a minimum slew rate and a maximum slew rate using RCdevices; determining, by the delay generator, at least one intermediateslew rate based on the minimum slew rate and the maximum slew rate usinga delay control apparatus of the delay generator; storing, by the delaygenerator, the minimum slew rate, the maximum slew rate, and the atleast one intermediate slew rate; receiving, by the delay generator,data from the serializer, wherein the received data is in the slew mode;and generating, by the delay generator, the delay on the received datausing the stored minimum slew rate, the stored maximum slew rate, andthe stored at least one intermediate slew rate.
 15. The method of claim14, wherein the determining of the minimum slew rate and the maximumslew rate using the RC devices comprises: receiving, by the delaygenerator, a half-rate clock from the PLL; applying, by the delaygenerator, the half-rate clock to the RC devices to generate a delayedhalf-rate clock; extracting, by the delay generator, a differencebetween the received half-rate clock and the delayed half-rate clock;and determining, by the delay generator, whether the difference iswithin a threshold range of the slew mode, wherein the threshold rangecomprises the minimum slew rate and the maximum slew rate; performing,by the delay generator, one of: adjusting the difference using afeedback mechanism in response to determining that the difference is notwithin the threshold range of the slew mode and storing the minimum slewrate and the maximum slew rate, or storing the minimum slew rate and themaximum slew rate in response to determining that the difference iswithin the threshold range of the slew mode.